Ink-jet printing head and ink-jet printing apparatus

Abstract

An ink-jet printing head and an ink-jet printing apparatus can reduce fluctuation of density of an ink ejected from each nozzle by ejecting ink of different densities from the same nozzle without varying size of an ink droplet, or by controlling ejection of a mixture ink, in which a plurality of inks are mixed, for forming an image. The ink-jet printing head includes a plurality of ejection openings for ejecting ink, a plurality of ink passages communicated with the plurality of ejection openings, ink ejecting energy generating elements provided in the plurality of ink passages, a mixing liquid chamber connected to the plurality of ink passages in common, a plurality of individual liquid chambers supplying ink to the mixing liquid chamber, and a valve mechanism provided between the individual liquid chamber and the mixing liquid chamber and controlling supply amount of the inks supplied from the individual liquid chambers.

What is claimed is:  
     
       1. An ink-jet printing apparatus comprising: 
       an ink-jet printing head including:  
       a plurality of ejection openings arranged in a row for ejecting ink;  
       a plurality of ink passages respectively communicating with said plurality of ejection openings;  
       ink ejection means provided in said plurality of ink passages;  
       a common liquid chamber connected to said plurality of ink passages in common;  
       an ink supply portion for supplying the ink to said common liquid chamber;  
       control means, provided between said ink supply portion and said common liquid chamber, for controlling a supply amount of the ink supplied from said ink supply portion;  
       an atmosphere communication opening, arranged on an extension of the row of said ejection openings, for communicating said common liquid chamber with outside;  
       first capping means for placing said ejection openings within a first sealably enclosed space;  
       first suction means for reducing a pressure within said enclosed space between said first capping means and said printing head;  
       second capping means for placing said atmosphere communication opening within a second sealably enclosed space;  
       second suction means for reducing a pressure within said enclosed space between said second capping means and said printing head; and  
       wherein said first suction means and said second suction means are driven at respectively independent timing.  
     
     
       2. An ink-jet printing apparatus as claimed in  claim 1 , which further comprises a carriage for moving said printing head for scanning, and a waste ink absorbing body extending along a scanning direction of said printing head at a position overlapping with a range in which printing by said printing head on said printing medium can be performed, for receiving waste ink discharged from said printing head. 
     
     
       3. An ink-jet printing apparatus as claimed in  claim 2 , wherein said printing head discharges the waste ink toward said waste ink absorbing body during movement.